Cylindrical Tool Pin Profile Research Articles

Experimental and optimization studies of friction stir processed Cu-TiB2 surface composites

The present study aims to fabricate different Copper surface composites (Cu-SCs) such as Copper-Silicon Carbide (Cu-SiC), Copper-Boron Carbide (Cu-B4C), Copper-Titanium Diboride (Cu-TiB2) with enhanced mechanical properties using friction stir processing. The Cu-SCs were fabricated at different levels of tool rotational speed (TRS), traverse speed (TS), and Vol. % of micro-sized Boron Carbide (B4C), Silicon Carbide (SiC), and Titanium Diboride (TiB2) reinforcements using blind hole method. The mechanical characteristics such as ultimate tensile strength (UTS), yield strength (YS), percentage of elongation (%EL), impact toughness (IT), and microhardness (H) of the Cu-SCs were evaluated and analyzed. In the next stage, the process parameters were optimized using a graph theory algorithm and utility concept and the TRS, and TS were 1120 rev/min, and 40 mm/min respectively. The Cu-SCs fabricated by using taper threaded cylindrical tool pin profile at four Vol.% of TiB2 possess enhanced the mechanical characteristics such as UTS, YS, % EL, IT, and H up to 282.07 MPa, 197.76 MPa, 12.96%, 16.67 J, and 168.6 HV. This was happened due to the increased recrystallization temperature, the pining effect, and restricting the grain boundary sliding. The microstructure in the stir zone of Cu-SCs fabricated with 4 Vol. % of SiC, 4 Vol. % of B4C, and 4 Vol. % of TiB2 particles exhibit fine grains. This is attributed to uniform distribution of the particles in the copper surface composites. The mechanical characteristics were also correlated with microstructures and fracture features.

Characterization and optimization of weld properties due to the effect of different pin profiles for AA8011 – based friction stir welding

PurposeThis Friction stir welding study aims to weld thick AA8011 aluminium plates, and the interface joints created with a variety of tool pin profiles were examined for their effects on the welding process.Design/methodology/approachScanning electron microscopy and optical microscopy and X-ray diffraction were used to examine the macro and micro-structural characteristics, as well as the fracture surfaces, of tensile specimens. The mechanical properties (tensile, hardness tests) of the base metal and the welded specimens under a variety of situations being tested. Additionally, a fracture toughness test was used to analyse the resilience of the base metal and the best weldments to crack formation. Using a response surface methodology with a Box–Behnken design, the optimum values for the three key parameters (rotational speed, welding speed and tool pin profile) positively affecting the weld quality were established.FindingsThe results demonstrate that a defect-free junction can be obtained by using a cylindrical tool pin profile, increasing the rotational speed while decreasing the welding speeds. The high temperature and compressive residual stress generated during welding leads to the increase in grain size. The grain size of the welded zone for optimal conditions is significantly smaller and the hardness of the stir zone is higher than the other experimental run parameters.Originality/valueThe work focuses on the careful examination of microstructures behaviour under various tool pin profile responsible for the change in mechanical properties. The mathematical model generated using Taguchi approach and parameters was optimized by using multi-objectives response surface methodology techniques.

Influence of pin profile on formability of friction stir-welded aluminum tailor-welded blanks: an experimental and finite element simulation analysis

In sheet metal forming processes, the forming limit diagram is frequently employed as a criterion for predicting necking initiation. This is one of the most useful and effective methods for the evaluation of the formability of tailor-welded blanks. The goal of this study was to determine the formability of friction stir-welded (FSW) aluminium alloy 6061-temper 6 (AA6061-T6) and aluminium alloy 2017-temper 6 (AA2017-T6) by employing five dissimilar tool pin profiles. To evaluate the limiting dome height, five different combinations of dissimilar blanks were used in experimental and simulation experiments. Material characteristics such as density, elastic modulus, and all multilinear behaviors of blanks were manually assigned for simulation from the test results of true stress versus true strain plots. The punch with die supports was considered as a rigid body, whereas the metallic blanks were considered as plastic material. To carry out the simulation, the entire blank was divided into three zones. The results obtained from the experimental and simulation results showed that the straight square tool pin profile is the optimal tool pin profile for the formability of FSW AA6061-T6 and AA2017-T6. The tested height values obtained from the limiting dome height were 20.5 and 20.9 mm in experimentation and simulation, respectively. The straight cylindrical tool pin profile exhibited the worst formability properties in both experimentation and simulation.

Experimental and optimization studies of ultrasonic-assisted friction stir weldments of AA2014-T651 using graph theory

The present study focuses on development of mechanical characteristics in ultrasonic vibration assisted friction stir welding (UAFSW) of AA 2014-T651 weldment using graph theory algorithm and utility concept. A set of UAFSW experiments were carried out using plain and taper threaded cylindrical tool pin profile on AA 2014-T651 weldments at different levels of tool rotation speed and traverse speed and experimental results for the tensile strength, yield strength, percentage of elongation, impact strength, and micro hardness were collected. Microstructural studies were also made and correlated with the mechanical characteristics and found that the mechanical characteristics were increased. The process parameters were optimized by the proposed methodology as 1100 rpm of tool rotational speed and 40 mm/min of traverse speed. The tensile strength, yield strength, percentage of elongation, impact strength, and micro hardness were found to be 431.69 MPa, 307.47 MPa, 11.66%, 8.32 J, and 139 HV respectively at optimum working condition. The weld joint obtained using a taper threaded tool pin profiled tool with ultrasonic vibration possesses 90% of joint efficiency.

Multi-Objective Variable Neighborhood Strategy Adaptive Search for Tuning Optimal Parameters of SSM-ADC12 Aluminum Friction Stir Welding

This research presents a novel algorithm for finding the most promising parameters of friction stir welding to maximize the ultimate tensile strength (UTS) and maximum bending strength (MBS) of a butt joint made of the semi-solid material (SSM) ADC12 aluminum. The relevant welding parameters are rotational speed, welding speed, tool tilt, tool pin profile, and rotation. We used the multi-objective variable neighborhood strategy adaptive search (MOVaNSAS) to find the optimal parameters. We employed the D-optimal to find the regression model to predict for both objectives subjected to the given range of parameters. Afterward, we used MOVaNSAS to find the Pareto front of the objective functions, and TOPSIS to find the most promising set of parameters. The computational results show that the UTS and MBS of MOVaNSAS generate a 2.13% to 10.27% better solution than those of the genetic algorithm (GA), differential evolution algorithm (DE), and D-optimal solution. The optimal parameters obtained from MOVaNSAS were a rotation speed of 1469.44 rpm, a welding speed of 80.35 mm/min, a tool tilt of 1.01°, a cylindrical tool pin profile, and a clockwise rotational direction.

Effects of tool pin profile on the formation of friction stir processing zone in AA1100 aluminium alloy

In the current investigation the effect of tool pin profiles (threaded cylindrical and straight cylindrical) on the mechanical properties (ultimate tensile strength, percentage elongation and joint efficiency) of friction stir welded and friction stir processed aluminium alloy (AA1100) was investigated. Taguchi L-18 array was used to select the transverse and rotational speed of the tool. The three distinct variables (tool shape, speed and feed rate) were used during investigation. From the results it was found that the joint fabricated by threaded tool profile gives maximum tensile strength and percentage elongation than the straight cylindrical tool pin profile. It is also found that, the threaded tool pin have good joint efficiency as compared to cylindrical tool i.e. maximum of 90% at 1800 rpm and feed rate of 50 mm/min. The joint constructed by threaded tool have maximum percentage elongation (8.38%) at 2400 rpm and feed rate of 45 mm/min. In addition, the joints fabricated by threaded tool pin profile have exhibited more ductility than cylindrical tool profile.

Investigation on Parameter Contribution to the Property of Weld Joint AA5052-H112 Sheets in Friction Stir Spot Welding under Fatigue Load and Failure Mode

In an initiative to reveal the property of welded joint, investigation and assessment of the welding parameters in friction stir spot welding (FSSW) was carried out. In this study, the AA5052-H112 sheets with 2mm thickness was welded using cylindrical tool pin profile under different combinations of main process parameters i.e. spindle speed, tool depth, and dwell time. The fatigue test under cyclical load condition was performed to investigate the dynamic behavior of the welded joint. Failure mode analysis on the fracture of the weld joint after fatigue test was took also consideration. Finally, results from the test were evaluated using analysis of variance (ANOVA) to deter-mine statistically significant factors and associated percentage contribution together with the generation of main effects plots. From ANOVA results, dwell time had the highest influence on fatigue load with a PCR of 52.8%, followed by the spindle speed 37.1%, and then tool depth 6%.

Shape memory alloy reinforced magnesium matrix composite fabricated via friction stir processing

Shape memory alloys (SMAs) are the new generation functional material and being recognized as a smart or intelligent material. In this research, a novel Ni-rich NiTip shape memory alloy (SMA) reinforced magnesium matrix composites were prepared using a recent solid-state friction stir processing (FSP) technique. High speed steel was selected as tool material. A flat shouldered plain cylindrical tool pin profile was selected for experiment. The FSP was performed on a fixed value of 560 tool rpm, 100 mm/min traversing speed and 3° tool tilt. The particle distribution in processed zone was analyzed using optical micrography while micro-hardness were evaluated by Vickers indentation test. The results revealed that the FSP was successful in fabrication of surface composite on magnesium matrix. The processed zone indicates good bonding of reinforcement particles with the substrate. However, some accumulation of reinforcement was observed in the processed region. The micro-hardness of the reinforced zone shows significant improvement.

Effect of Cylindrical Tool Pin Profile of Friction Stir Welded Composite with Similar and Dissimilar Joints

Effect of Cylindrical Tool Pin Profile of Friction Stir Welded Composite with Similar and Dissimilar Joints

Prediction and Experimental Validation of Peak Temperature in Friction Stir Welded AA2024 with AA5083 by Response Surface Methodology

Objective: The work aims at prediction of the peak temperature using Response Surface Methodology. Methods/ Statistical Analysis: Dissimilar Aluminum Alloys AA2024 and AA5083 O were friction stir welded. A fifteen run 3 factorial 3 level Box Behnken design was conducted and temperature generated were measured at both sides of the alloys. Thermocouples were employed for the same. The temperature was recorded and studies conducted. Response surface plots were used to obtain the peak temperature and effect of various parameters. Findings: The relationship between the process parameters and the temperature were established using ANNOVA. Mathematical models were development which can apply for future predictions. The traverse speed, rotational speed and the tool profile contributed to the temperature generation. The peak temperature was obtained at 1200 rpm, 25 m/min and threaded cylindrical tool pin profile. Application/Improvements: The temperature at the re-treating side was recorded to be higher compared to the advancing side. Keywords: Anova, Heat Input, Mathematical Modeling. Peak Temperature, RSM

Influence and Optimization of Input Parameters on Mechanical Properties of Friction Stir Processed AA 2014-T6

The Friction Stir Processing (FSP) parameters such as spindle speed, feed, tilt angle and tool pin profile possess an impact on the mechanical properties of FSP samples significantly. The experiments were designed based on Taguchi’s technique. The investigation was set to analyze and develop an empirical model for the prediction of output responses namely ultimate tensile strength (UTS), yield tensile strength (YTS) and percentage of elongation (% E) using response surface method (RSM). The influence of FSP parameters on tensile parameters/properties of friction stir processed samples are studied in detail. Out of five different tools selected, FSP samples processed using hexagonal tool pin profile exhibits maximum tensile strength, YTS and percentage elongation whereas cylindrical tool pin profile have the lowest of the output responses. Multiple performance optimization was carried out to optimize the parameters using desirability approach based RSM. The analysis of results was carried out using Analysis of Variance (ANOVA) to assess the adequacy of the response surface methodology. The results of the model indicate that the experimental values were in close proximity to the predicted values at 95% confidence level.

Experimental Investigation of Mechanical Properties And Morphological Studies on Friction Stir Welded Aluminum 2024 Alloy

In this research work, some important investigations were carried out to find out the changes in the macro, microstructures and mechanical properties of the Aluminum 2024 alloy. It is clearly understood through experimentation that friction stir welded components exhibits remarkable morphological and mechanical properties with proper selection of tool geometry, rotational speeds and feeds which greatly influence the weld quality and the weld strength. The present trialing uses taper cylindrical tool pin profile with different process parameter values under constant axial load of 3 kN were considered. Further the study reveals that tool rotational speed of 1000 rpm, feed rate of 30 mm /min are best suitable for the selected work material which produces tensile strength of 300MPa and high yield strength of 280MPa with parent metal along with marginal tunnel defect.

Effect Of Different Tool Pin Profiles On The Joint Quality Of Friction Stir Welded AA 6063

In the present paper an attempt has been made to investigate the effect of different tool pin profiles on the joint quality in terms of tensile strength during Friction stir welding (FSW) of 6063 aluminium alloy. 4.75 mm thick plates of AA6063-T6 were welded using FSW. Five different pin profiled tools of hot die steel were employed. Results of the study revealed that tapered cylindrical tool pin profile exhibited maximum tensile strength. Also, formation of tunnelling defect in the welded joint was discussed and recommendations of elimination/minimization of this defect were made.

Effects of Tool Pin Design on Formation of Defects in Dissimilar Friction Stir Welding

Friction stir welding is an automatic process, falls under the category of solid state welding processes. In this study, friction stir welding was carried out on dissimilar copper to aluminum materials by nine different tool designs. Present investigation provides an insight on formation of defects under the effect of different tool pin designs. The tool pin profiles such as cylindrical, triangular, square and hexagonal were used in the present experimental investigation by keeping other parameters constant. These tool pin profiles were designed based on its static and dynamic constant areas from best suitable cylindrical profile. Besides, the defects were analyzed through visual observation, macrostructure, microstructural investigation and scanning electron microscope. The results revealed that, the copper particles detached from base material were large and irregular in case of polygonal pin designs. Maximum irregular and large copper particles were reported in welds made by triangular pin profiles. Additionally, polygonal pin profiles were generating defects such as voids, tunnel, cracks and fragmental defects irrespective of its static and dynamic constant areas. Furthermore, defects were decreased as the polygonal edges increases. Defect free macro joint was reported for cylindrical tool pin profile.

Effect of Process Parameters on Mechanical Characterization of Dissimilar Friction Stir Welded Aluminium Alloys

Aluminum alloys exhibit poor weldability by conventional fusion welding process. The heat treatable aluminum alloy AA2014 is extensively used in the aircraft industry because it has good ductility and high strength to weight ratio. In this paper the effects of welding parameters and tool profile on the mechanical properties of friction stir welded butt joints of dissimilar aluminum alloy sheets AA6082 and AA2014. The process parameters such as rotational speed, transverse speed and axial forces were considered. The effect of parameters on weld quality was analyzed. Hardness and tensile tests are carried out at room temperature to examine the mechanical properties of the welded joints. The joints produced with straight square tool pin profile have higher ultimate tensile strength, whereas the straight cylindrical tool pin profile results in lower tensile strength.

Influence of tool design and process parameters on dissimilar friction stir welding of copper to AA6061-T651 joints

In the present investigation, two different tool designs along with different process parameters such as tool pin offset, welding speed and axial plunge load were used to produce dissimilar copper to aluminium (6061-T651) friction stir welding joints. Macrostructure and microstructure analysis, tensile test, hardness measurement test, scattered electron microscopy and electron-dispersive tests were performed to evaluate the weldability and weld properties of dissimilar copper–aluminium joints. The results revealed that defect-free dissimilar friction stir welding was achieved using a cylindrical tool pin profile. On the other hand, the taper tool pin profile was not found to be suitable for dissimilar friction stir welding system (FSW). Maximum tensile strength of 133 MPa and hardness of 181 HV (in the nugget zone) were obtained when FSW process parameters such as rotational speed, welding speed, tilt angle, tool pin offset and tool pin profile were kept at 1500 rpm, 40 mm/min, 2°, 2 mm and cylindrical profile, respectively. Axial plunge load value depended on the shoulder diameter as well as on the tilt angle. Axial plunge load range from 600 to 700 kgf was used to achieve defect-free copper to AA6061-T651 (of 6.3 mm in thickness) friction stir welded joint.

Microstructure and Mechanical Properties of Friction Stir Welded Pure Copper

Abstract. Conventional welding of copper and its alloys tends to degrade the mechanical strength at the welded area due to high thermal diffusivity and melting point. Friction stir welding (FSW) is an excellent alternative for joining of these materials against fusion joining. FSW is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The main objective of this investigation is to use FSW for joining of 3 mm thick copper sheet using taper cylindrical tool pin profile. The defect free welds were obtained at a tool rotational speed of 900rpm and 1120 rpm and traverse speeds of 25, 31.5, 40 and 50 mm/min respectively. Mechanical and microstructure analysis has been performed to evaluate the characteristics of friction stir welded copper. From the investigation it is found that the joints fabricated at a tool rotation speed of 900 rpm and traverse speed of 40mm/min resulted in better mechanical properties compared to other tool rotation and traverse speeds. The tensile properties of all the weld joints showed a relative correspondence to the variation of the hardness in the weld zone. The observed results were correlated with the microstructure and fracture features.

Effect of Welding Speed on Mechanical Properties of Friction Stir Welded Copper

Fusion welding of copper and its alloys tends to degrade the mechanical strength at the weld joint area due to high thermal diffusivity and high melting point. Friction Stir Welding (FSW) is an excellent alternative for joining of these materials against fusion joining. FSW is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non- consumable tool to generate frictional heat in the abutting surfaces. The main objective of this investigation is to use FSW for joining of 3 mm thick copper sheet using taper cylindrical tool pin profile. The defect free welds were obtained at a tool rotational speed of 900 rpm and traverse speed of 25, 31.5 and 40 mm/min respectively. Mechanical and microstructure analysis has been performed to evaluate the characteristics of friction stir welded copper. From the investigation it is found that the joints fabricated at a traverse speed of 40mm/min resulted in better mechanical properties compared to other traverse speeds. The tensile properties of all weld joints showed a relative correspondence to the variation of the hardness in the weld zone. The observed results were correlated with the microstructure and fracture features.

Experimental Investigation of Tool Geometry on Mechanical Properties of Friction Stir Welding of AA 2014 Aluminium Alloy

The AA 2014-T6 is widely used in the air craft structure and truck body. The alloy cannot be welded by gas welding techniques due to poor weldability. Welding of this Al alloy by Arc & Resistance welding require special techniques & hence costly. The most suitable method for welding AA 2014-T6 is Friction Stir Welding Process. The effect of Friction Stir Welding process parameters on the mechanical properties of the AA 2014-T6 alloy joints produced by friction stir welding have been discussed in this study. The defect free welds were obtained at a tool rotational speed of 900rpm, taper cylindrical tool pin profile and traverse speed of 40mm/min respectively. Mechanical and microstructure analysis has been performed to evaluate the characteristics of friction stir welded AA 2014-T6. From the investigation it is found that the joints fabricated at taper cylindrical tool profile with 3mm radius of curvature resulted in better mechanical properties compared to straight cylindrical tool profile.

Influence of Tool pin Profile on the Microstructure and Mechanical Behavior of Cu/SiC Metal Matrix Composites Produced by Friction Stir Processing

Friction stir processing (FSP) is a metal-working technique that causes microstructural modification and change in the upper surface of metal components. In this work the effects of tool pin profile on the microstructure and mechanical behavior of reinforced SiC particles metal matrix composites (MMCs) produced by friction stir processing were studied. Optical microscopy (OM) and Scanning electron microscopy (SEM) was employed to carry out the microstructural observations. Vickers Microhardness Machine used for microhardness evaluation. Results show that, tool pin profile play a major role in improvement of the surface quality, SiC particles dispersion in pure copper matrix, hardness behavior and wear resistance. Two different tool pin profile (straight cylindrical and square) were used to perform the process. It was found that, straight cylindrical tool pin profile led to finer grains, uniform dispersion of SiC particles, higher microhardness and wear resistance values.